<xs:complexType name="BoundarySurfacePropertyType">
	<xs:annotation>
		<xs:documentation>Denotes the relation of an _AbstractBridge to its bounding thematic surfaces (walls, roofs, ..). The
			BoundarySurfacePropertyType element must either carry a reference to a _BoundarySurface object or contain a
			_BoundarySurface object inline, but neither both nor none. There is no differentiation between interior surfaces bounding
			rooms and outer ones bounding bridges (one reason is, that ClosureSurface belongs to both types). It has to be made sure
			by additional integrity constraints that, e.g. an _AbstractBridge is not related to CeilingSurfaces or a room not to
			RoofSurfaces.</xs:documentation>
	</xs:annotation>
	<xs:sequence minOccurs="0">
		<xs:element ref="_BoundarySurface"/>
	</xs:sequence>
	<xs:attributeGroup ref="gml:AssociationAttributeGroup"/>
</xs:complexType>